Device fob sevebing glass



is heated by the UNITED VSTATES PATENT OFFICE.

HARRY F. HITNER, 0F WILKINSBURG, PENNSYLVANIA, ASSIGNOR TO PITTSBURGH PLATE GLASS COMPANY, A CORPORATION OF PENNSYLVANIA.

DEVICE FOR SEVERING GLASS.

Specification of Letters Patent.

Patented Nov. 16, 1920.

` Application led November 4, 1919. Serial No. 335,611.

To all whom t may concern.

Be it known that I, HARRY F. HITNER, a citizen of the United States, and a resident of Wilkinsburg, in the county of Allegheny and State of Pennsylvania, have made a new and useful Invention in Devices for Severing Glass, of which the following is a specification.

The invention relates to devices for severing or cracking glass by the application of heat `along the desired line of division. The device is primarily designed forcutting up the glass cylinders from which Window glass is made, but may be used upon other circular glass articles or even upon -il'at glass if so desired. The objects of the invention are the provision of a compact and simple device, which can be operated with great rapidity and certainty, which requires little skill in operation, and which is more durable than the type now in use in which the wire passage of electricity through the wires.

Briefly stated the device comprises a portable heating chamber carrying a reel upon which a wire or chain is wound. The wire or chain is heated while wound on the reel, and when ready for use is pulled out and placed around the cylinder to be divided. After this operation the wire is wound back into the reel, preferably by means of a spring, although this may be done by hand ,if desired, and reheats very rapidly by reason of the heat stored in the chamber and reel. The chamber is preferably heated by a nichrome heating element, and this heating may be continuous or intermittent. In the latter case the chamber may bemore conveniently handled by the operator, be-

cause of the absence of the supply wires.y

The chamber may also b e similarly heated continuously or intermittently by other means such as by gas, the invention con-' templating broadly the luse of a portable heating chamber with a reel therein carrying a flexible heating element or the use of the reel without the. chamber, and any and all means for heating the reel or chamber.

Certain embodiments of the invention are illustrated in the accompanying drawings, wherein:

Figure l is a vertical section through one form of device; Fig. 2 is a partial side elevation and partial section on the line II-II of Fig. l; Fig. 3 is a partial face view of the heating element; Figs. 4 and 5 are enlarged views showing portions of the flexible heating members which may be employed; and Fig. 6 is a partial section through a modified form of construction. y

As shown in Figs. l and 2, the casing of the device consists of a pair of sheet metal shells l and 2 with an insulating material 3 therebetween, such insulating material being any suitable refractory material which is relatively non-conducting, such as asbestos or kieselguhr. Extending transversely of the casing is a shaft 4: mounted in the bearings 5 and 6 located upon the outside of the casing. The shaft 4 is preferably made hollow so that there will be a less tendency to overheat the bearings and such bearings are preferably of the ball or roller type, which are less affected by heat than solid bearings. The left hand end of the shaft is secured to a clockspring 7 mounted in a casing 8 adapted to bring the reel carried by the shaft back to starting position when the wire which has been withdrawn from the casing is released.

The reel itself comprises a solid block of metal 9, upon which the wire or chain l() is wound, as indicated in Fig. l. It is desirable that the block 9 should be solid so as to provide a large amount of stored heat for heating the wire or chain after it is withdrawn inside the casing. In case a wire or cable is used it should, of course, be relatively as flexible as possible, and to this end it is preferably of the woven type, as indicated in Fig. 5. A relatively large wire may thus be used which retains a large amount of heat and renders the cracking off relatively easy. Various materials may be used, but the preferred material is nichrome, which does not oxidize and is practically indestructible. In Vsome cases it may be desirable to use a chain instead of the Wire or cable, such a chain being illustrated in lFig. 4L This gives a very flexible member,

which is desirable, but one which does not hold the heat as long as a Wire or cable of the same weight and does not give as good contact against the glass.

Y The heating element preferably comprises a porcelain ring 12, having a groove 13 on-V each side (Fig. 1) and a-plurality of transverse grooves let. In these grooves is Wound the heating Wire 15, also preferably of nichrome, theends of these Wires leadingto suitable terminal block- 16.011 the-outside'ot' the casing, to Which the4 cable 17 carrying` the leading in Wires is attached.

A slot18risprovided through one side of thecasing Iand the porcelain ring, to permit Y Y Wire from being drawny into the casing too venience Various other means might ob-1A inder. A Withthe glass. heats it so that it may be far. Enough offtheWire-is thus left to proj ect from the casing so. that theend does not become too Warm to handleivithout incon` viouslybe provided .for securing arcool end upouthev wire. In order to conveniently manipulate the casing a handle 21 is secured thereto.

Inoperating thev device current is supplied to the heatingelement.until the WireV 'orf chainbecomes sufficiently heated, after which they cableiswithdrawn from the casing and passed around theV article to be severed, such, for instance, as a glass cyl- The contactv of the Wire or chain readily cappedv or. crackedV off along'the line of Contact. After theY operation is complctedfthe free end' ofthewire isre leased andthe spring on the casing windsV the cable back into the: reel, Where it becomes reheated Jfor another operation, this y reheating operation occurring rapidly be- 1 cause. of the. heat retained inthe casing and in-th'ereelupon Which the Wire is Wound.

Fig. 6 'illustrates a modifiedconstruction in which the heatis accomplished by means otra. gas jet. InVthis construction the casing 22..and reel 23 are` the sameas in the other construction, but. the electric heating element` is omitted` and anopening 2a provided in the casing, through Which the end` Y 25, ot a .Biinsen burner projects.

o/devicescan` be employed at the same- A number time so that' one of them is always ready for. use,jand,it is not necessary to reheat after each sever-ing.;v operatirni,l as suhicienti. heatrw'ill be retained `in the casing Vandreel to reheat the Wire for anumber of operations befoieit again becomes necessary to place the device over a burner.

In this construction aV suitable base 26 is provided for the casing, so that it Will rest .securely upon the supporting table 27,

detach-the leadsfduring the use ot the apparatus, if so desired.

What I claim is: l n l. In combination in a-glass cracking off device, a heating chamber, a reel in the chamber, a flexiblecracking oft. member Wound onthereel and adapted to be Withdrawn from the chamber, and means/:tor heating the chamber. Y

2. In combination in a glass cracking off device, a heating chamber, a reelin the chamber, a flexible cracking oli member Wound on the reelandfadapted -to be -Withdrawn from thechamber, a'vspring tending to turn the reel-and Wind the saidfmember upon the` reel,Y and means for heating vthe chamber.l Y .Y

3. In combination in a glass cracking olf chamber, a iexible cracking off member woundronrthe reel and adapted to'be -vvithdrawn from the chamber, andan electricalA heatingV element for heating the chamber;

if. In combination-in a glass cracking-'olf device, a heating chamber, al reel in the chamber, a Vli-exible cracking oii`"niember Wound on thereel and' adapted to be withY drawn from the-chamber, a' spring upon the outside of the "chamber tendingl to turn .the

rreel and Wind' said member upon the reel,

and means for heating the chamber.

5. .In combination in a glass crackingV o5 device,raV heatingl chamber, a reel in the chamber, a -flexible 'crackingl olf member Wound'on the reel andadapted tobe Withi Y device, a'heating chamber,'a reel in the IOO device, aheating chamber, a reel ini thek chamber, a, flexible Vcrackingoft'l member comprising a" pluralityA `of strands of s fine Wire Woven; together andi adaptedi toV be Withdrawn from. the chambenand; means i 25 Y for-heatingthe chamber. Y

7; In 4combination `in a glasscrackingotf device, Vavreel', anexible metal cracking ott member on. the; reel, means'tor applying heat so that the terrible member -sfheated Y130Y on the reel to a temperature such that it Will crack off a glass article when Withdrawn from the reel and applied to such article, and means for Winding the flexible member back on the reel after the cracking off operation.

8. In combination in a glass cracking off device, a reel, a flexible metal cracking off member on the reel, means for applying 10 heat so that the exible member is heated on the reel to a temperature such that it will crack off a glass article when Withdrawn from the reel and applied to such article, and a spring for turning the reel to Wind the flexible member thereon.

In testimony whereof, I have hereunto subscribed my name this 1st day of November, 1919.

HARRY F. HITNER, 

